Browsing by Author "Schryvers, Anthony B."
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Item Open Access Bacterial receptor binding regions on human lactoferrin and bovine transferrin(2001) Wong, Henry; Schryvers, Anthony B.Item Open Access Characterization of the periplasm to cytoplasm branch of the ferric iron uptake pathway(2002) Lam, Siu Ling; Schryvers, Anthony B.Item Open Access Cloning, characterization and construction of an isogenic mutant of the pseudomonas aeruginosa asd gene: potential use in vaccine delivery and in vivo expression technology systems(1995) Hoang, Tung T.; Schryvers, Anthony B.Item Open Access Conserved Interaction between Transferrin and Transferrin-binding Proteins from Porcine Pathogens(Journal of Biological Chemistry, 2011-06-17) Silva, Leslie P.; Yu, Ronghua; Calmettes, Charles; Yang, Xue; Moraes, Trevor F.; Schryvers, Anthony B.; Schriemer, David C.Gram-negative porcine pathogens from the Pasteurellaceae family possess a surface receptor complex capable of acquiring iron from porcine transferrin (pTf). This receptor consists of transferrin-binding protein A (TbpA), a transmembrane iron transporter, and TbpB, a surface-exposed lipoprotein. Questions remain as to how the receptor complex engages pTf in such a way that iron is positioned for release, and whether divergent strains present distinct recognition sites on Tf. In this study, the TbpB-pTf interface was mapped using a combination of mass shift analysis and molecular docking simulations, localizing binding uniquely to the pTf C lobe for multiple divergent strains of Actinobacillus plueropneumoniae and suis. The interface was further characterized and validated with site-directed mutagenesis. Although targeting a common lobe, variants differ in preference for the two sublobes comprising the iron coordination site. Sublobes C1 and C2 participate in high affinity binding, but sublobe C1 contributes in a minor fashion to the overall affinity. Further, the TbpB-pTf complex does not release iron independent of other mediators, based on competitive iron binding studies. Together, our findings support a model whereby TbpB efficiently captures and presents iron-loaded pTf to other elements of the uptake pathway, even under low iron conditions.Item Open Access Ferric binding proteins: Identification and role in the rion acquisition pathways of the pasteurellaceae and neissericaceae(2000) Kirby, Shane Douglas; Schryvers, Anthony B.Item Open Access Genome-wide analysis of response to production of a foreign outer membrane protein(2003) Kolodka, Dione Uliana; Schryvers, Anthony B.Item Open Access Identification of the transferrin binding regions of the Neisseria meningitidis transferrin binding protein B (TbpB)(1996) Fuller, Cynthia Ann; Schryvers, Anthony B.Item Open Access Identifying the binding domains of transferrin to its bacterial transferrin receptor(1995) Alcantara, Joenel; Schryvers, Anthony B.Item Open Access Interactions between transferrin and transferrin binding protein B(2008) Shima, Collin H.; Schryvers, Anthony B.Item Open Access Interactions of an iron uptake pathway(2006) Yu, Raymond; Schryvers, Anthony B.Item Open Access Intercations between transferrin and transferrin binding protein B(2008) Shima, Collin H.; Schryvers, Anthony B.Item Open Access Iron acquisition from lactoferrin by pathogenic members of the neisseriaceae(1997) Bonnah, Robert Alexander; Schryvers, Anthony B.Item Open Access Lactoferrin binding protein B - a bi-functional bacterial receptor protein(PLOS Pathogens, 2017-3-3) Ostan, Nicholas K. H.; Yu, Rong-Hua; Ng, Dixon; Lai, Christine Chieh-Lin; Pogoutse, Anastassia K.; Sharpe, Vladimir; Hepburn, Morgan; Sheff, Joey; Raval, Shaunak; Schriemer, David C.; Moraes, Trevor F.; Schryvers, Anthony B.Lactoferrin binding protein B (LbpB) is a bi-lobed outer membrane-bound lipoprotein that comprises part of the lactoferrin (Lf) receptor complex in Neisseria meningitidis and other Gram-negative pathogens. Recent studies have demonstrated that LbpB plays a role in protecting the bacteria from cationic antimicrobial peptides due to large regions rich in anionic residues in the C-terminal lobe. Relative to its homolog, transferrin-binding protein B (TbpB), there currently is little evidence for its role in iron acquisition and relatively little structural and biophysical information on its interaction with Lf. In this study, a combination of crosslinking and deuterium exchange coupled to mass spectrometry, information-driven computational docking, bio-layer interferometry, and site-directed mutagenesis was used to probe LbpB:hLf complexes. The formation of a 1:1 complex of iron-loaded Lf and LbpB involves an interaction between the Lf C-lobe and LbpB N-lobe, comparable to TbpB, consistent with a potential role in iron acquisition. The Lf N-lobe is also capable of binding to negatively charged regions of the LbpB C-lobe and possibly other sites such that a variety of higher order complexes are formed. Our results are consistent with LbpB serving dual roles focused primarily on iron acquisition when exposed to limited levels of iron-loaded Lf on the mucosal surface and effectively binding apo Lf when exposed to high levels at sites of inflammation.Item Open Access Peptide(2001) Sims, Kurtis Lyle; Schryvers, Anthony B.Item Embargo Peptide : peptide interactions between transferrin and transferrin binding Protein B(2001) Sims, Kurtis Lyle; Schryvers, Anthony B.Item Open Access Periplasmic to cytoplasmic iron transport in neisseria meningitidis(2000) Khun, Heng Henry; Schryvers, Anthony B.Item Open Access Phenotypic and genotypic characteristics of respiratory isolates of the streptococcus milleri group from patients with cystic fibrosis(2012) Grinwis, Margot E.; Surette, Michael G.; Schryvers, Anthony B.Item Open Access Structural analysis of iron acquisition proteins(2006) Shouldice, Stephen R.; Schryvers, Anthony B.Item Open Access Structural Variations within the Transferrin Binding Site on Transferrin-binding Protein B, TbpB(Journal of Biological Chemistry, 2011-04-08) Calmettes, Charles; Yu, Rong-hua; Silva, Leslie P.; Curran, Dave; Schriemer, David C.; Schryvers, Anthony B.; Moraes, Trevor F.Pathogenic bacteria acquire the essential element iron through specialized uptake pathways that are necessary in the iron-limiting environments of the host. Members of the Gram-negative Neisseriaceae and Pasteurellaceae families have adapted to acquire iron from the host iron binding glycoprotein, transferrin (Tf), through a receptor complex comprised of transferring-binding protein (Tbp) A and B. Because of the critical role they play in the host, these surface-exposed proteins are invariably present in clinical isolates and thus are considered prime vaccine targets. The specific interactions between TbpB and Tf are essential and ultimately might be exploited to create a broad-spectrum vaccine. In this study, we report the structure of TbpBs from two porcine pathogens, Actinobacillus pleuropneumoniae and suis. Paradoxically, despite a common Tf target, these swine related TbpBs show substantial sequence variation in their Tf-binding site. The TbpB structures, supported by docking simulations, surface plasmon resonance and hydrogen/deuterium exchange experiments with wild-type and mutant TbpBs, explain why there are structurally conserved elements within TbpB homologs despite major sequence variation that are required for binding Tf.Item Open Access The role of haemophilus influenzae fbpa in iron transport(2007) Khan, Ali Gauher; Schryvers, Anthony B.